Childhood obesity is at historically high levels in the US, and epidemiological data indicate that childhood obesity and physical inactivity track into adulthood and have been associated with a variety of cancers. Therefore, addressing the obesity epidemic is particularly important given its projected impact on the health care system. Policy approaches (i.e., state laws) governing the school environment have been identified as strategies to address childhood obesity and promote healthy eating and physical activity. The Classification of Laws Associated with School Students (CLASS) was created as a resource and research tool to track the strength of state laws governing the school nutrition and physical education/activity environment.